text:
Why there is no online radar coverage of Madagascar?
I noticed that no planes heading to FMMI are plotted on all the prominent online radars despite the fact that most of them are likely equipped with ADS-B.
What does it take to remedy that lack of coverage?

people with ads-b receivers living in madagascar and providing data to such online radars?

possible duplicate of ATC real-time traffic services

For services like FlightRadar24 they typically get data in two ways: via volunteers hosting ADS-B receiver stations on the ground, and directly from the ATC radar system in places where that data is readily available.
For the ADS-B equipped aircraft these services would need volunteers in the area of Ivato Airport (FMMI) to host ADS-B receivers. They would almost certainly be happy to have more receivers, and they even offer free "premium" services (and occasionally free receivers) to people who help provide data. If it's legal in your area, and you are willing to run a receiver station you may want to look into it, and this will get you aircraft which are broadcasting ADS-B data (Mode S+ES with GPS position information).
For the aircraft which are not broadcasting ADS-B information (because they lack an appropriate transponder or GPS system) the problem is a little more complicated - the organization that runs ATC in Madagascar would need to set up radar sites (which presumably exist), and make that information publicly available (which may or may not be the case). A system would then need to be developed to allow the online radar services to process that data and make the flight tracks available (subject to whatever delays may be imposed in that process).
As I don't know much (anything really) about the ATC system in Madagascar, so I'm not sure how robust the radar infrastructure is or how open they might be with their data, so I can't really comment on that half of the system.

Ok. I'm afraid the ATC body is lagging behind here. Crowdsourcing is likely the way to go. I've overlooked the legal issue. Thanx for the indepth answer.

What are the legal issues? Obviously anything that transmits is regulated, but passive receivers? The data is not secret.

@JanHudec: The legality of passively receiving radio signals is typically not concerned with the realities of physics.

@JanHudec Laws often have very little to do with reality.

@voretaq7: Yeah, the kind of law that hinders innocent activities while not really hurting the actual wrongdoers because the violation can't be detected if kept secret.

@JanHudec There are many places where receivers are illegal... Or certain kind of receivers. For example in quite a few countries it's illegal to have airband receivers and radios capable of picking up police frequencies. In some it's a crime to have any receiver that can be tuned to different frequencies from those preprogrammed to receive government sanctioned broadcasts even...

@jwenting: True. I should have remembered it was forbidden to listen to Radio Free Europe around here too (and now it broadcasts from here to other countries where it is forbidden to listen to it).


text:
What is the total pressure of an air stream in motion?
This question is from a French aeronautics exam so I translated as best I can but I suck at these terms in English. Anyways, can someone please explain this question to me because I'm just really confused by other explanations.
In an air stream in motion, the total pressure is equal to:
- difference between dynamic pressure and static pressure.
- sum of dynamic and static pressures.
- difference between atmospheric pressure and dynamic pressure.
- sum of static and atmospheric pressures.

The total pressure assumes that the is an isentropic evolution from air in movement up to an static state. The total pressure is the pressure at such state.
The way to compute this "made up" variable you need to compute the static pressure and the dynamic pressure (driven by the air speed).
So the answer is:

the sum of the dynamic and static pressure

But remind that is not "a real property" but more a way to measure the maximum pressure that can be achieved from a fluid in movement without adding extra energy.

source: Stack Exchange

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sort: votes


text:
Where can I find good data on volume of air traffic?
I want to have a look at air traffic fatalities data, and have found good information on number of accidents, like this on AviationSafety.
For comparison I want some (world-wide) data on passenger air traffic volume, like number of flights (journeys) per year, or passenger-km per year. So far I couldn't find it. Some good reference?

For $799 you can buy IATA's World Air Transport Statistics (WATS)
IATA publish a few summary data values in various reports

Scheduled Passenger - Kilometres Flown
Scheduled Passengers Carried
IATA Annual Review 2013
IATA Annual Review 2014
IATA Statistics

Note that I think this is data is only collected from IATA members and much of the data is for western-built jets (figures for other manufacturers are much worse, according to comments in IATA reports)
Passenger Km
Total (International + Domestic)

Rank  Airline                   Millions
1     United Airlines           286,802
2     Delta Air Lines           277,560
3     Emirates                  209,377
4     American Airlines         206,551
5     China Southern Airlines   147,841
6     Southwest Airlines        145,124
7     Lufthansa                 144,236
8     Air France                136,405
9     British Airways           130,129
10    Qantas Airways            110,203

The 2.97 billion passengers travelled in the last slide – is that a total over several years? Or is that the number for 2012?

I think extensive world-wide statistics will be very difficult to compile since it would be spread across so many sources. There are  Narrowing it down to Europe and America I think would make it a lot easier...
I did a search with reference to ICAO, the International Civil Aviation Organisation (a branch of the UN), but the data appeared to be behind a paywall. The World Bank however does have data for most countries, again based on ICAO data.
Some nice and detailed data for America appears can be found at the Bureau of Transportation Statics, part of the Department of Transportation.

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What configuration of autothrottle is required when pilots are landing an Airbus?
Do Airbus pilots normally disengage the Auto Throttle on a manual landing?
Do pilots (Airbus or Boeing) normally prefer a manual landing to a A/P landing?

Answers the second question.

According to Boeing published flight procedures, A/T is engaged in BEFORE the takeoff procedure and is automatically disconnected 2 seconds after landing. But do Airbus pilots need to manually engage A/T ?And do they disengage on Final approach?

A/T, as all other systems, has to be manually engaged, there is no system that "turns itself on" automatically. when they Retard (put the levers to IDLE) A/T is disengaged.

Do Airbus pilots normally disengage the Auto Throttle on a manual landing ?

Depends on what you mean.
During the initial part of the approach, no, they do not deactivate the autothrust (not autothrottle, in this case):

But the autothrust is not designed for landing and just before touchdown there is an automatic callout in the cockpit: Retard. Retard. (it can be heard in this video 4 times).
The callout is needed because of the A/THR inner working: while in SPEED mode it can apply any throttle between 0 and the current throttle lever position; i.e., if for example the throttle is at the 80% setting, the autothrust can apply any throttle between 0% and 80% (based on the required airspeed). At the Retard callout the pilots will move the levers to the IDLE position, effectively deactivating the autothrust:

Most (but absolutely not all) pilots let the aircraft land itself most of the time.  I asked a number of different pilots this question (30+ year captain at USAirways, a 3 year FO at Spirit, a 20+ year captain at Delta) and their estimate was that 75% or more of landings were done via auto-pilot.  One of these pilots was almost exclusively Boeing, one was almost exclusively Airbus, and the other estimated that his experience was roughly 60% Boeing.

Weird. I've heard mostly the opposite, that most prefer to hand-fly the landing as much as possible and just use auto-land often enough to stay current or when field conditions require it.

and most airports don't even have the equipment to do autolandings, so those numbers look exceedingly dubious. Approaches flown on autopilot, yes. Pilots putting in the numbers given by ATC and let the machine steer the aircraft. But final approach and landing has to be hand flown or you're illegal on most runways.

This sounds like you're confusing an autopilot-flown instrument approach with auto land.

@jwenting even when an airport has the equipment for CAT II/III ILS approaches, it does not mean it is operating in CAT II/III mode and then you really shouldn't attempt an autoland or this happens: https://aviation.stackexchange.com/questions/910/why-dont-pilots-always-use-autoland/914#914

@Bianfable I never said as much...

@jwenting Agreed! I just wanted to add that the equipment alone is not enough.

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Does an A320 revert to Direct Law if both engines flame out?
In the case of a  flame-out in both engines on the two-engine A320, does the aircraft revert to Direct law or does it maintain Normal Law?
An example is US Airways 1549 (the landing on the Hudson).

The airplane will no longer be in normal law mode if both engines fail and no other electrical generator is online.
The airplane needs a primary source of electrical power in order to remain in normal law (among other things of course). If both engines lose power, then the generators on those engines also lose power. The only other primary electrical source is the APU generator. In addition to the batteries, the RAT (ram air turbine) is also available to supply electric power (along with hydraulic power) in an emergency situation. In this mode, the flight controls reconfigure to alternate law until a generator is brought back online.
From the US Airways 1549 report, page 88:

...the captain started the APU, which improved the outcome of the ditching by ensuring that a primary source of electrical power was available to the airplane and that the airplane remained in normal law and maintained the flight envelope protections

You say it changes to alternate law, but your quote says normal law

@raptortech97  Starting the APU prevented it switching to alternate law. Because the APU was running, the plane stayed in normal law

@mjs Ohhhh! That makes way more sense!

When both engines have failed, the A320 reverts to alternate law. However the pitch law is replaced by the direct law upon landing gear extension. The side stick movement directly controls the elevator position. It means that side stick input is proportional to flight control output. The THS is mechanically controlled from the trim control wheel. No protection is included.

do you have any source? (pilot handbook or similar?)

According to https://www.skybrary.aero/index.php/Flight_Control_Laws

As is the case with ALT1, some failure cases that result in ALT2 will
  also cause the autopilot to disconnect. ALT2 is entered when both
  engines flame out, with faults in two inertial or two air-data
  reference units, with faults to all spoilers, certain aileron faults
  or with a pedal transducers fault.
In Alternate Law 2 (ALT2), Normal Law lateral mode is lost and is
  replaced by roll Direct Law and yaw Alternate Law. Pitch mode is in
  Alternate Law. Load factor protection is retained. In addition to
  those protections lost in ALT1 (Pitch Attitude and Low Energy
  Protection), Bank Angle Protection is also lost. In some failure
  cases, High Angle of Attack and High Speed Protections will also be
  lost.


text:
What is the time before an alarm is given after a fire sensor perceives a fire?
I've got a very specific question:
When a fire sensor perceives a fire, does it wait 20 or 60 seconds before giving the alarm?

This may well be the most specific question we have at Aviation!

FreeMan thanks for editing, sometimes I forgot the basic grammar...!

The fire sensor's time to give the alarm is customizable depending upon the fire safety alarm being used. Two widely used types of continuous-loop systems are the thermistor type detectors, such as the Kidde and the Fenwal systems, and the pneumatic pressure detector, such as the Lingberg system. (Lindberg system is also known as Systron-Donner and, more recently, Meggitt Safety Systems.). A typical delay of 10 Seconds is quite common. Here is the Source for your further reading


text:
What does an absolute novice need to learn to make a successful emergency landing?
Suppose I am a passenger in a small, non-commercial plane (e.g. at most 8 seats), and the pilot suddenly dies or is otherwise incapacitated mid-flight. Suppose further that nobody else on the plane knows the first thing about flying, or that I were the only other person on the plane. I understand the basic physics of flying, and have been in airplane cockpits before for a ride, but never piloted one. Cockpits are an intimidating bank of switches and dials, and I imagine I'd have very little time to acquaint myself with them experimentally in an emergency.
What minimalistic, general information should I know in an emergency situation to try to land a small plane?
I'm looking for perhaps 5–10 fast-and-simple rules-of-thumb that would be useful in a life-or-death situation, yet easy to remember.
A great answer might include 2–3 sentence answers for things such as:

Where might I expect to find certain, key controls?
How could I contact air traffic control?
What kind of terrain should I aim for, if possible?
What rate of descent is too dangerous?
How to deploy landing gear? (What might this button look like?!)
How to control the aircraft speed, and how slow is too slow?
How might I determine a good angle of attack?

Similar question (but not necessarily a duplicate): Pilot passed out in a small GA plane. What can a passenger do?

Welcome to aviation.SE! As Tanner said, we have a very similar question already; it would probably be helpful if you could add something about how your question is different, otherwise people may vote to close yours as a duplicate.

Thanks to @TannerSwett for pointing that out — it's definitely close! Whereas that question was intended for somebody familiar with planes (e.g. "initiated to fly a plane" and "100s of hours on flight sims"), my question is intended for somebody with essentially zero experience with planes: I don't know how to turn an engine on/off, or how to operate the radio. I expect that the answer for these questions would be different based on the different levels of familiarity with aircraft. I'm also interested what people would consider most immediately important.

@jvriesem You have to assume some familiarity and knowledge, not least because there is no single standardised cockpit layout when it comes to knobs and switches. Many knobs and switches have labels, but they are very abbreviated or technical. Unlike cars where you have almost (but not entirely) identical controls laid out relative to the driver which are sufficient for complete control; the only familiar controls in the pilot's seat that are (almost) always in the same position are the yoke, throttle and pedals, but those alone are not sufficient if you hope to land in one piece.

You may find this question relevant: Why are the cockpit controls of airplanes so complicated?

@aerobot One doesn’t have to assume familiarity. This question assumes that the person has no familiarity — by fiat. The variety in cockpits is a big part of why I asked the question!

To quote from an old, old, Soviet joke: "Tel Aviv Ai Control to Air Egypt flght 311: Repeat after me: ".

Welcome new user!  Best to quickly read Hypnotizing Maria by Richard Bach  :)

As far as what kind of terrain to aim for... I'd recommend a runway, personally. Preferably a long and wide one. While that's generally not needed for landing a light airplane, it would be helpful in case you end up too high/fast on final (easy to do) and/or are landing in a crosswind or something like that. No sense in trying to land a perfectly flyable airplane anywhere other than a runway, though (unless maybe you're flying over salt flats out West, in which case you can land pretty much anywhere.)

@jvriesem I guess you clarified your question after it was first posted? (Laymen not acquainted with flight at all wouldn't have the slightest idea about angle of attack.) If not, then I may have been too hasty and did not read your question properly when it was first loaded up. Anyway, it's perfectly clear now, and my comment seems redundant =/

I would say talk some to the pilot before departure. If the pilot tells you anything that contradicts any of this, forget this and go with what the pilot tells you! They know the airplane far better than any stranger you'll find on the Internet.
Ask them to point out the important controls; throttle, yoke or stick, elevator trim, and how to change the frequency on the radio and transmit, will probably get you pretty far. The transponder IDENT button and flaps selector may also be useful, but especially flaps will require a bit of care. Elevator trim generally isn't critical, but it is very nice to have.
Ask them to point out the important instruments; airspeed indicator, altimeter, vertical speed indicator, compass, and fuel gauges, will again probably get you pretty far. Those will tell you where you are relative to the ground or to sea level (altimeter), where you're going (compass), how fast you're going (airspeed, vertical speed), and how much longer you can go (fuel gauges).
The exact control layout varies by aircraft, both type and (specific) airframe. However, the instruments typically look very similar.
In an emergency like what you describe, most of what's in the cockpit is entirely superfluous! If you don't know what it is, and the pilot doesn't discuss it when asked what's important, it's probably pretty much safe to just ignore, as long as you don't touch it. I actually disagree with mmathis' answer that the attitude indicator is important; there are many aircraft that don't even have one. Most of GA is flown in what's known as VMC, or Visual Meteorological Conditions, under VFR, or Visual Flight Regulations. Basically, that's the same as in a car; you're (the pilot is) looking out the window, using terrain features below to navigate and the horizon in front to keep the plane level. VFR flight in good weather is not rocket science!
Even landing a functional airplane in good weather on a wide, long runway isn't rocket science.
The hard part of flying is handling the bad situations: equipment malfunctions, strong crosswinds on landing, poor weather conditions aloft (including IMC, or Instrument Meteorological Conditions), etc. Or when ATC asks you to do something like land and hold short thus reducing the runway length by half, then vacate the runway quickly before that 747 on your tail touches down...
The first thing you'd probably want to do is to make sure the pilot isn't slumped over any controls. Tighten their harness to keep them from falling forward and interfering with the instruments or controls. This may involve moving their arms or even legs. Don't hesitate to do so if needed. The plane isn't going to immediately fall out of the sky.

Where might I expect to find certain, key controls?

Most if not all will likely be either in front of the pilot, or in the center of the instrument panel (assuming a side-by-side seat configuration). With the exception of big planes, controls and instruments in front of the right-hand seat will likely be more for monitoring the health of the airplane than for actively flying it. Radios and navigation equipment may also be located on the right hand side.

How could I contact air traffic control?

Locate the radio (usually labelled COM or COM1, possibly VHF/VHF1, but this may differ depending on the type of radio installed and the type of aircraft you're in). It will normally have two frequency readouts, one "active" and one "standby" (or similar).
If the pilot was already talking to ATC, just press the transmit button and speak into the microphone. Speak clearly, speak slowly (but not overly so; about 100 words per minute is good), say "mayday" a few times followed by the call sign of the aircraft you're in if you know it, let go of the button and see if someone responds. If not, try again once or twice. If still no response, set the radio to a frequency of 121.5 (MHz), set that frequency as active, and make the same transmission again. Exactly how to do this will depend on the specific radio; the pilot can show you before departure how to change the frequency.
121.5 MHz is the international emergency frequency and is monitored by ATC at all times. It is also monitored by aircraft able to do so. You will be able to reach someone on 121.5. Worst case it'll only be another aircraft, but they can relay to ATC.
As soon as you reach somebody, tell them that you are not a pilot nor a student pilot. This information is critical for them to best help you. You could say something like "I am not a pilot. Negative flight experience.". ("Negative" here means "no", not "below zero".)
Don't worry about what exactly to say. Just try to speak normally and describe the situation. ATC will ask for any details they need to help you, or for clarification if they need it. If you don't speak the local language, it's safe to say that all air traffic controllers internationally speak English. Don't make overly long transmissions; I'd say more than 20 seconds or so at a time is on the long side.
Once ATC knows about your situation, they will do everything they can to direct any other aircraft out of your way, as well as help you out in any other way they are able to. Don't hesitate to ask them for anything you feel that you need which they might be able to provide, including your position or the direction in which you should be flying.

What kind of terrain should I aim for, if possible?

A runway.
No, seriously. It's always easier to set down an aircraft on a clearly visible runway than to do an outfield, or even a soft field, landing.
Failing that, any large, flat terrain clear of obstacles will do for landing in a pinch. Beware of ditches, fences and power lines! Especially if you're attempting to land somewhere that is not an airport, always make sure to tell ATC what you're doing so that they can direct emergency services your way.

What rate of descent is too dangerous?

While still in the air, that isn't a major concern. While headed for a runway, there really are only two important things to keep in mind. First, don't fly into terrain. Second, don't hit the runway too hard and too fast. If you're unsure, it's better to level off, or even "go around" by adding full power, climbing to altitude, and making a wide half-circle for another attempt. (Again, I'm assuming here that there are no problems with the airplane.)
If the runway is equipped with PAPI (precision approach path indicator) lights, that's a big help, as you can just descend at a rate that keeps two lights red and two lights white. If more than two lights are white then you increase your rate of descent; if more than two lights are red then you level off.
The only part where the rate of descent is going to make a lot of difference is during the last few dozen meters or less above the runway. This is where you flare (raise the nose of the aircraft). The flare serves several purposes: (a) it reduces your speed from flying speed to below flying speed; (b) it ensures that the main wheels touch down before the nose wheel; (c) it arrests the descent, and (d) it transitions the airplane from flying in the air to rolling on the ground. A really well executed flare can transition the airplane from flying to rolling almost imperceptably, but the odds of a complete novice managing that seem near zero.
If you raise the nose too much during the flare the airplane will start climbing during the flare while losing speed. If you're too high at the top of the flare, the airplane will drop hard onto (hopefully) the runway below. If you're too low at the top of the flare, you won't have time to arrest the descent (resulting in a hard landing) or the nose wheel may contact the runway before the main wheels. If the nose wheel touches down first, there's a very high probability of losing control.

How to deploy landing gear? (What might this button look like?!)

Have the pilot point it out to you. Most small aircraft don't have retractable landing gears, so this may or may not even be an issue.
If the airplane you're flying does have retractable landing gear, note that (a) you can't deploy it while flying too fast (there should be a plaque next to the control indicating maximum speed at which it can be deployed), and (b) once deployed, it will increase the drag of the airplane, so you'll need more engine power to maintain speed or rate of descent.

How to control the aircraft speed, and how slow is too slow?

Engine power is controlled by the throttle. Speed is controlled by a combination of engine power and pitch.
There is no single number for "too slow", even for a specific airplane, but assuming you're flying gently, not doing any abrupt maneuvers, it should be good enough to keep the airspeed well within the green arc on the airspeed indicator. When coming in to land, keep the airspeed near the faster end of the combination of the green and white arcs. This won't be exact by any means, but it should be good enough that you won't seriously risk breaking anything important.
Assuming a fixed power setting, the airplane will fly slower when you raise the nose, and faster when you lower the nose.
Assuming a fixed pitch and starting at level flight, the airplane will (eventually) climb when given more power, and descend when given less power.
Hence the saying "power for altitude, pitch for speed". Especially during landing, this is the opposite of what is likely to feel natural! It certainly took me a number of times to internalize that if you're too low on the final approach to the runway, the last thing you want to do is raise the nose! (I knew it intellectually, but it's quite another thing to actually internalize so that the correct response becomes second nature.)

How might I determine a good angle of attack?

Don't.
Just fly level. As long as you are well above the surrounding terrain, just keep half an eye on the vertical speed indicator, keep it right around zero until you've found a landing site, and you're basically golden.
Angle of attack is important, but not for the kind of flying a passenger might do following pilot incapacitation.

Anything else?

No, you didn't actually ask this one, but it bears saying: Probably the most important maneuevering you might do in such a situation is to stay well away from clouds. There's a number of hazards involved with clouds, and the easiest thing to do is to just steer clear of them. For one, mountains have been known to hide out in clouds...
Also, never forget to fly the airplane first and foremost. Keep it in the air, and keep it away from terrain. Everything else can wait. If ATC asks something, you can always just tell them to "stand by". Just let them know when you're able to talk to them again.

So, to summarize:

Talk to the pilot. Five minutes before start-up or departure to look over the cockpit can make this a lot easier.
If something like this happens, then immediately tighten the pilot's harness, or otherwise make sure that they won't interfere with instruments or controls.
The airplane isn't going to immediately fall out of the sky. You do have time to breathe.
Don't worry about all the extra stuff in the cockpit. It's probably safe to ignore in the situation you're in.
Landing a functional airplane on a large runway in good weather isn't rocket science.
The most important instruments and controls will likely be in front of the pilot's seat.
Saying "mayday" on 121.5 MHz will get you attention from air traffic control, as well as other aircraft in the area. Once you have their attention, they will do whatever they can to help you. Tell ATC up front that you're not a pilot.
Aim for a runway, if at all possible. If you can't, then aim for flat, open, unobstructed terrain.
Don't worry too much about the particulars. Fly level and stay away from terrain.
Add power if you need to climb; reduce power if you need to descend. Push the yoke or stick forward to go faster; pull it toward you to go slower.
Keep the airspeed indicator well within the green arc.
Avoid clouds. They are not your friend.

Great answer, but I'd say things are in wrong answer. Rule is "aviate, navigate, communicate, in that order". Reading your answer top to bottom, it appears that the guy should first trying to figure out how to manage the radio, instead of first maintaining correct plane attitude.

@kebs You have a point. My idea was to answer the specific questions posed by the OP in the order they were posed.

ATC has successfully talked down folks with zero experience in GA planes, and if there's one thing you need to learn, it's how to call ATC so they can give you that help.  Any pilot would be happy to teach you this, and it should only take a few minutes while you're sitting in the plane before departure.  Anything you know beyond that will make ATC's help a lot easier to understand and get you safely on the ground that much faster, but that's the bare minimum.
My recommendation is a "discovery flight" at a nearby flight school; that will teach you far more of the basic skills you'd need to survive than days of looking for tips online.  Flight sim time would save money if you're interested in becoming a pilot, but otherwise I wouldn't bother; you need to actually sit in a real plane, touch real buttons and knobs and levers, and feel how a real plane reacts--with someone at your side explaining the key points along the way.  I learned every one of the things on your list and more, plus made my first landing, in that one hour lesson.
FWIW, it doesn't matter if that discovery flight is in a Cessna and your emergency happens in a Mooney, or whatever.  For light planes, most of the differences border on cosmetic for emergency purposes.  Once you know what to look for and why, it shouldn't take much to recognize the important controls and instruments in any other light plane.  Again, any pilot you're flying with should be happy to explain the differences if you don't pick them up on your own; an instructor is only needed when you're starting from zero.
If you'll be flying GA a lot, particularly in the same plane and/or with the same pilot, look into "Pinch Hitter" courses; they'll cost quite a bit more than a simple discovery flight, but they're worth every penny if you'll be flying often enough for real concerns about emergencies.

"ATC has successfully talked down folks with zero experience " - see https://www.bbc.co.uk/news/uk-england-humber-24457031  for example.

I believe Mythbusters even had an episode where real ATC controllers tried to talk the hosts through landing a (simulated!) passenger jet. IIRC success was about 50%... so its not hopeless even in the "worst" case!

That's way too complicated a question.  The best thing you can do is get MS Flight Simulator and learn to fly one of the light planes on it.  It even has lessons in it.  You can easily learn enough to survive the real deal if that ever happened and you had access to the controls. Instructors these day frequently get new students who've spent time with FSX and are surprisingly advanced right at the start.
Other than that, the most important thing for a passenger to know is how to tune the communications radio to the emergency frequency 121.5 and how to broadcast on it.  This will get you in contact with the nearest air traffic unit, wherever you are (they all monitor it) and you would be able to be talked down.  It's been done a number of times.
Have your host show you how to control the plane in level flight, enough to keep in level flight and do basic turns (very easy).  If you can do that, and can get ATC on the radio on your own, you'll be able to make it down.  You'll be steered to a suitable airport with a nice big runway and told what to do step by step.  No worries.

Sure, I could invest dozens or hundreds of hours in a flight sim, but I'm asking what the first things to know are for someone who doesn't want to invest that much time in learning to fly. :-) +1 for the rest of the answer, though!

Flightgear is free, and in half an hour, your are able to fly/land pretty much the plane. Or at least to figure out the basics.

One of  my favourite Aussie expressions....

But the crux of OP's question is about how to cope with differing controls. Adding yet another control scheme (keyboard and mouse) is the opposite of clarity.

Well a joystick is a given.  Anyway, it doesn't matter about the computer controls, it's about making the "sight picture" and inputs/outputs you see in the virtual cockpit familiar.

Funny that John gave a great answer, but the OP wasn't satisfied since he wanted something 'easy' that doesn't require any time investments. THERE ARE NO SIMPLE TIPS TO DO SOMETHING COMPLICATED LIKE LANDING A PLANE

If you think this is ever likely to occur to you, you should look into a Pinch Hitter class
https://www.aopa.org/community/flying-clubs/flying-club-newsletter/2017/august/20/safety
where you will get more in depth in addition to what's already been offered.

Pilot incapacitation is extremely rare during general aviation flights, but non-pilots may worry about it if they don’t know what to do in the event of an actual emergency. Introducing non-pilot flying companions to basic flight concepts, and how to handle emergency situations, can help calm this anxiety.
Enter the early 1960s, the AOPA developed the Pinch Hitter™ course to do just that. Through the course, non-pilots learned to navigate to an airport, talk with air traffic control, and land an airplane safely—all on their own.
Today, your flying club members can tap into two free resources designed to be used together in pinch hitter training—the AOPA Air Safety Institute (ASI) course that provides non-pilots an interactive introduction to GA aircraft along with an understanding of basic aerodynamics concepts, and ASI’s recently developed Pinch Hitter™ syllabus.
The 14-page syllabus booklet guides non-pilot flying companions, flight instructors and experienced pilots through Pinch Hitter™ training. It also expands on the knowledge that participants gained from the course, and suggests ground and flight lessons to cover aircraft orientation and scenario-based training. The latter provides hands on instruction to deal with a simulated emergency. In addition, an in-flight guide and emergency checklist complete the syllabus booklet.

This is a fairly broad question, as there are a lot of possible airplanes you could be flying in, all with a variety of possible avionics and flight control configurations. But, there are two main types of avionics - the so-called "six pack" of analog instruments and glass displays. Both display the same basic information, but in different ways.
The first thing you'll probably want to do is gain or maintain control of the plane. Keep it flying level, at sufficient altitude, with sufficient speed. You'll look for these 3 pieces of information in 3 analog instruments:
The attitude indicator (this one showing a nose-up attitude of ~10 degrees and wings level).

The altimeter (this one showing an altitude of ~10,200 ft).

And the airspeed indicator (this one showing an airspeed of ~92 knots).

If the plane has glass avionics, these are all combined into one Primary Flight Display (PFD) (this one showing an altitude of ~2700 ft, an airspeed of 175 knots, and a slight nose-up attitude of 4 degrees and wings level).

In all cases, these instruments should be directly in front of the pilot, although there may be similar instruments in front of the copilot as well. You'd want to get your instruments showing a wings level, slight nose-up attitude, with the altitude not changing and the airspeed constant and in the green arc. If it's already doing that, no need to change anything.
If it's not in a stable configuration, your best bet is probably to add full power (throttle is typically a black lever for each engine, push it / them all the way in or all the way up for full power). The yoke controls attitude, pull back to raise the nose, left or right to bank, push in the lower the nose.
Once you have control of the plane, your next step is to contact somebody who can help you land the plane. Grab the pilot's headset and put it on. If the pilot was already talking to ATC (you hear voices through the headset), keep talking to them; there's no need to change the frequency. Most control yokes have a Push-to-talk (PTT) switch located on them somewhere, which will transmit your voice over the frequency. Wait slightly for a break in the chatter, push the PTT, and say "Mayday" or "Emergency". That should get everyone's attention, and then ATC can get additional information from you and provide help to you. If you can include your tail number with your initial "Emergency" call, all the better (the tail number is placarded somewhere in the cockpit, possibly in front of the pilot on the instrument panel, and will begin with an 'N' for US aircraft).
If there is no chatter through the headset, you should change the frequency to 121.5, the emergency frequency. There's too many possible radio configurations to go through here, but one thing to keep in mind is that most aircraft radio stacks have multiple communication radios and multiple navigation radios. Each of those likely has an active frequency and a standby frequency. When you're changing the frequency, you'll be changing the standby frequency; you'll then have to switch it to the active frequency. This is done with a little button with a double-arrow on it (<-->). Make sure you change the comm frequency - when in doubt, change the one at the top of the stack.
A discovery flight is a great way to get acquainted with a lot of these instruments and controls, as would a couple hours on a PC flight sim. You could probably also find some videos online going over the basics.

flying a plane, specially a small one requires a lot a practice, but if you find your self in this situation, and assuming is a small prop, complex twin engine aircraft (Variable prop, retractable landing gear).
Where might I expect to find certain, key controls?
all the controls are in the front panel, 3 levers in the mid control panel, black for thrust, blue for prop, red for fuel, don't touch red and blue, move black, back to reduce power and forward to increase
How could I contact air traffic control?
usually on the yoke is a small button (ptt) press it and talk, or by the microphone, set on the radio the frequency 121.50
What kind of terrain should I aim for, if possible?
try to maintain level wings, aim for an airport
What rate of descent is too dangerous?
try to maintain between 500 to 700 fpm rate of descent
How to deploy landing gear? (What might this button look like?!)
depends on the aircraft, usually black rounded knob on the panel, usually on the right side, it moves up and down, look for it.
How to control the aircraft speed, and how slow is too slow?
the airspeed indicator has colors, try to maintain the speed on the green band
How might I determine a good angle of attack?
it depends on the speed, and configuration, but a good indication is the rate of descent and constant speed, aim for 500 fpm descent maintaining speed on the green band
safe flights

If you're in a GA plane, and the pilot just flops over dead, then you only really need two pieces of information to make your survivability acceptable.

Take a deep breath. Most GA plans are built so that very little input is needed to keep them flying. It's not like a movie where you take your hand off the controls and the plane spins out of control. The pilot before dieing would have done all of the steps to keep the plane level and flying (trimming, autopilot, fule setups, etc) So just take a deep breath and calm down. Don't go touching anything. Not yet at least.
How to use a radio, at least a little. Your next step would be to contact anyone that could help. Your cell probably won't work, so that means using the radio. Don't worry the pilot already did the hard part of tunning it. You just have to figure out how to talk on it. That depends, but it's usually very easy to figure out. Yell into the mic "May-Day! Our Pilot is dead!" then shut up for 45 seconds. Rinse and repeat until someone tells you what to do. The people on the other side will know what to do, and how to "talk you down". You may not have a smooth landing, but you should have a survivable one.

The important part is to stay calm, and don't touch things. Planes don't fly themselves exactly, but they are built so the default in most situations is to not crash.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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How should the number of maintenance hours per flight hour for the C-17 be interpreted?
While reading up on the Boeing C-17 Globemaster III, I came across a reference to its maintenance man-hours which surprised me. As listed in the spec sheet (emphasis mine):

These requirements include an aircraft mission completion success probability rate of 92 percent, only 20 aircraft maintenance man-hours per flying hour, and full and partial mission availability rates of 74.7 and 82.5 percent, respectively.

Now this strikes me as a rather steep maintenance requirement, especially considering the spec lists "only 20 hours". If I understand that statement correctly, for every hour spent in flight, 20 technicians have to spend that same amount of time maintaining the plane after landing.

Do those 20 hours refer to an average over extended operation of the aircraft? In other words, does this include extended maintenance where the plane might be undergoing days of intensive maintenance, skewing the numbers?
Is this a low number for this class of aircraft?
Do the required maintenance hours scale with: size, complexity, military/commercial use?

Reading on the types of checks on Wikipedia, it seems like this number might be an average but I'd question the usefulness of such a number if it is.

I am sure the raw data can be found somewhere in some document or budget line item but there are a few things to keep in mind.

These numbers may only be airframe maintenance preformed. According to this article it seems that P&W maintains the engines.
This article (a bit dated) states that the air force must only maintain 50% of the work in house. Again they may only be counting their hours.
The air force (and all military aircraft) are subject to their own regulations and intervals and such. Although they must play by FAA rules when flying in airspace their upkeep is to the standards set forth by the owning military body. This may make it hard to compare with general aviation or commercial aviation.

Do the required maintenance hours scale with: size, complexity, military/commercial use?

In general yes. A piper cub is going to be simpler to maintain per hour than say an F-16 but as you know things vary. I would say that the hours scale more with complexity than size. Mainly because from a mechanical stand point a more complex engine or aircraft would have more things to disassemble and go wrong and in turn more things to put back together generally increasing maintenance time. Keep in mind this is a very general statement.
In terms of military vs commercial use, you will see a lot more maintenance on a military fighter than a commercial plane largely as a result of design. Commercial planes have lots of redundant systems and reliable parts as they are selling safety. Fighters have lots of high performance parts, some redundancy and things that may be made to wear faster in order to preform. Again a general statement but you can get the gist.

Do those 20 hours refer to an average over extended operation of the aircraft? In other words, does this include extended maintenance where the plane might be undergoing days of intensive maintenance, skewing the numbers?

Im going to assume that this is an overall average but it may not be.

In the words of Benjamin Disraeli, there are three kinds of lies... Lies, Damn Lies, and Stastistics! As Dave has already mentioned, the devil is in the detail. I support his assumption that the 20 maintenance man-hour figure is an overall average.
By way of comparison, I often quote a figure of 12 maintenance man hours per flight hour. This is from an Australian Transport Safety Bureau paper written by Dr Alan Hobbs. He doesn't delve into the basis of this figure, so I have assumed it to be an industry wide, overall figure. In this context, I think that the 20 man-hours you cite for the C17 is entirely believable, being a complex, military aircraft.
FYI, Dr Hobb's paper - An Overview of Human Factors in Aviation Maintenance - can be viewed via this ATSB link:

This is an average. after some flights only routine servicing such as refueling and a preflight inspection before the next flight will be needed. After other flights, there may be several different maintainers working on several different issues. Also all aircraft require periodic inspections and maintenance. They can often involve dozens of maintainer and take several days to complete.
I never worked on the C17 aircraft. I worked on KC135A and B52G aircraft in the 1980's. I think for the tankers we figured 30 to 40 hours per flight hour and the bombers were around 100 hours per flight hour, but I cannot find any recorded figures.


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Where can I find a worldwide General Aviation incident/accident ocurrence reports database?
I enjoy reading reports about aviation incidents and accidents. There are often interesting technical details and I believe that this practice increases the safety of my flights.
To keep up to date I have set up a browser add-on which informs me daily about changes in the web-pages of several aviation safety agencies: NTSB, TSBC, IAC, BEA, AAIB, CIAIAC, BFU, SUB... This way I get to know about new occurrences and the publication of reports. However, depending on how each web page is structured, this method creates false positives, works only partially or doesn't work at all.
Is there any worldwide database or source informing about aviation occurrences and the publication of the corresponding reports?
I know about the Aviation Herald, but it only only deals with new occurrences on commercial aircraft. I'm especially interested in General Aviation and the publication of final reports.

There is not, as far as I know, a consolidated database for GA (or any) accident reports. The NTSB publishes reports of occurrences in other countries, but I think that is only when they are asked to participate in the investigation.

No such official worldwide consolidated general aviation accident database exists. Most countries have their own, many smaller countries have none.
The closest you will find to a consolidated aircraft accident database is the one maintained at the Aviation Safety Network's web site. However, this database does not qualify as an answer because it only covers airliner, military transport category aircraft and corporate jet aircraft safety occurrences since 1919, and then again only if the aircraft had 12 seats or more. Most other sites advertising such databases also have similar exclusions.

Please don't get into petty arguments in comments (now deleted). If you believe this to be an insufficient answer downvote it, leave a comment as to why (if you wish) and move on.

People who think absence of evidence is not evidence as absence should know that the burden of proof is on them to prove the statement. I'm done here. Thanks.


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How does one address a first officer in conversation?
If I am just deplaning a commercial flight and I see the captain (4 bars on the epaulet) and want to thank him/her for a safe and enjoyable flight, I would say "Excuse me, Captain, thanks for the nice flight".
However, if I were to encounter the first officer (3 bars), how should I address him or her? "Excuse me, First Officer...?"
Presumably not "Hey co-pilot!" :)

"Yo, gopher!" – but only if you want salt in your coffee instead of sugar :)

Ha, ha, why would you even bother to speak to a first officer? Nobody ever bothered to speak to me when I was a first officer. Just kidding, and I'm sure times have changed for the better in that respect. Personally, I would avoid the rather awkward "First Officer" and just say "Sir" or not use a direct address title.

The only time you should address the copilot is when the landing was particularly bad. In this case you just stick your head in the cockpit and speak toward the FO telling him to work on his landings. The purpose of this is to maintain the captains ego in case it was his landing.

I considered including the rest of my example comment for the FO (…how long do you think the plane will be in maintenance after that landing?) but I am flying this week...

I only compliment the auto pilot on a nice flight.  It's the one that deserves the credit!

@kjmccarx, don't you mean the programmers?

Surely? Shirley?

Call the FO 'Captain' anyway.

Both crewmembers are equally rated in the aircraft.
The FO might have more time in the aircraft than the captain or even have been a captain at a previous airline, but is sitting in the right seat because of low seniority at this carrier.
Nobody minds being referred to by a higher title.
You're a passenger, no one expects you to be able to read the bars on their uniform anyway.

Is it now required that both the Captain and the First Officer be type rated in the aircraft? I retired 15 years ago, and back then in the U.S. only the Captain had to be type rated and have a First Class medical. Typically the First Officer was not type rated unless they had flown the aircraft at a previous airline, and F.O.s could fly with only a Second Class medical.

@Terry it hasn't effectively changed.  FO now at a minimum now have an SIC type which is exactly what FO training used to be except someone signs an 8710 at the end.  No checkride from an APD, just the normal company check before being sent to IOE line training.

I believe it would be disrespectful to the captain to refer to his subordinate as the same rank.  (Reason for down vote)

@KeeganMcCarthy it isn't disrespectful.  Follow an aircrew around the airport sometime.  Everyone who works in the airport (shoe shiners, electric cart drivers, TSA agents, food vendors, shopping vendors, skycaps, taxi drivers, etc) will call the FO "captain".  We get used to it and no one is going to feel disrespected.  We don't expect the public to have a clue when it comes to what the stripes mean.

I address them both as sir/ ma'am.  That way it is just as respectable and won't make things awkward.

I think the appropriate term would simply be "crew". Since you may or may not have known who was the Pilot Flying (PF) on that good or terrible landing you can just say good job crew!

True, if I was hoping to address a specific part of the flight experience, like landing, which is attributable to the PF regardless of seat position. I don't know if "crew" would be appropriately respectful to the position of First Officer as a greeting, primarily since "crew" refers to more than one person.


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Transition from LSA to non LSA
If you obtain your PPL (Private Pilot License) in an LSA (Light Sport Aircraft), do you have to go for additional training or certification for other SEL (Single Engine Land) aircraft (ie. Cessnas), or how would that work?

Can you please write out what LSA and SEL mean in full? Also what country are you talking about?

I’ll assume from the terminology that you’re asking about FAA rules.
If you have a PPL ASEL, then as far as the FAA is concerned, you are legal to operate any ASEL that does not require any additional endorsement (complex, high performance or tail wheel) or a type rating.
However, in practice, it is highly unlikely you will be able to do so without additional training.  No insurer will cover you without a minimum amount of time in type, and nobody will rent a plane to you either because their insurer will require similar time in type. But how do you get time in type without already having that time in type?
This is solved by getting “transition” training. By the time that is complete and the CFI is satisfied you can safely operate the new type solo (which typically amounts to being able to pass a BFR/IPC, whether or not they do the paperwork making that official), you will probably have the minimum required hours.


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Relationship between Altimeter and Transponder
I'm wondering if there's a relationship between Altimeter, Mode C and Transponder. I'm asking because I understand that the Mode C transmits pressure altitude and aircrafts identification code to ATC and nearby aircrafts. If this is correct may I know how these components are connected to each other.

This question is similar to: Where does the transponder read altitude, or does ATC get it from radar?. If you believe it’s different, please [edit] the question, make it clear how it’s different and/or how the answers on that question are not helpful for your problem. -- see in particular my answer on that question.

This is really multiple questions in one, so while I suggested that the "what is Mode C" question is is a duplicate of another (really several) on this site, the others may not be... but they're all relatively quick and relatively connected, so here's a brief answer. I don't have the time to make it more brief.
You asked about:

Altimeter
Mode C
Transponder

The altimeter and the transponder are physical devices installed in an aircraft. Mode C is a communications/encoding protocol used by the transponder.

The altimeter is a device which indicates to the pilot what their altitude is. The altitude indicated is referenced to a certain altimeter setting. If the pilot has not set the altimeter to the proper setting, the indicated altitude will not be accurate.
The transponder can send two distinct pieces of information to ATC (and possibly other surrounding transponders), depending on which one the ATC radar has requested: Either a specific identifying 12-bit number, or the aircraft's pressure altitude encoded into Gillham code (a modified Gray code). The identifying number is called a "Mode A" response and the encoded pressure altitude is a "Mode C" response.

The transponder uses an "encoder" to translate the pressure altitude into the proper Gillham code. This encoder is distinct from the altimeter used by the pilot: The pilot can spin the altimeter setting up or down and that will change what they see on their instrument, but it will NOT affect the Mode C and so will NOT change what ATC sees on the radar scope.

Thanks its clear now


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Why is indicated airspeed rather than ground speed used during the takeoff roll?
My instructor asked me this question during my lesson and I couldn't come up with any answers. He asked why do I need to look at the indicated airspeed rather than ground speed when in takeoff roll or as soon as we touchdown?
It would be great if you could give me the reference to back it up.

Comments are to be used to request clarifications on the question. If you have comments about other comments, please use our main chat room

Because wings work on air moving past them, not ground moving below them.
Heck, in a 35 knot headwind, the Antonov-2 could be rolling backwards at 2 knots and still take off!

This is already explained in the existing answers. Why add one more?

@mast My explanation is far simpler.  Which seems to be warranted here.

Agreed, this is why carriers head into the wind. More than one aircraft landed with negative ground speed during WW1.

Other answers are based on the same ideas, but this one puts it most directly.

Sometimes the best answers are also the simplest.

Imagine if the wind dropped suddenly! :O

in a 35 knot headwind, the Antonov-2 could be rolling backwards at 2 knots and still take off! you sure that's a plane and not a motorized kite? +1 BTW.

For a moment my mind went to the Antonov-225 and promptly short-circuited.

Because what determines the amount of lift generated is the indicated airspeed, not the ground speed. As usual, it is always easier to think about an extreme case. If you have an aircraft with VR (speed at rotation for takeoff) of 90 knots, and there is an 80 knots head wind, in theory it will rotate with ground speed of 10 knots even though the indicated airspeed will be 90 knots.

Given this is a relatively simple question, probably best not to assume OP knows what Vr is.

@Notts90 True, but it seems like OP is a pilot or studying to become one. Let's hope they know what Vr is

@DeepSpace  yes, cf. "There is this procedure in my airline"

My guess is airline-sponsored primary training. I'd hope he knows what Vr is by now, but I'm not sure we can assume it was explained correctly if he's asking this question.

I don't remember offhand what every V speed means, and this site isn't exclusively for pilots anyway, so why not tell everyone what Vr is? Save some google searches.

For those interested: Vr is defined as the speed at which the rotation of the aircraft should be initiated to takeoff attitude.

Re, "...not the ground speed."  Also, not the true airspeed or any other speed. The IAS has the air density "baked in."

@DeepSpace While OP may be training to be a pilot, let's try to remember that SE is for everyone, and is likely to involve others viewing this question later who may not be training as a pilot. For that reason it's usually worth avoiding jargon or adding a quick explanation

See also, the infamous "Airplane on a treadmill" meme

Lets take an even more extreme case--there have been cases of GA aircraft "flying" while actually tied to the ground.

Airspeed is always important as it determines lift which keeps you in the air. At the moment of take-off or landing, airspeed is critical because it is the point at which you transition to or from flight; you need to be going fast enough but not too fast so that the transition is positive without being abrupt or overly stressful on aircraft components. This is why there are specified take-off and approach speeds.
Ground speed matters in navigation because it determines flight time which affects fuel required to get from A to B.
Ground speed is a consideration for take-off and landing (ideally kept to a minimum), which is why it's always preferable to do so into the wind, but ultimately it is airspeed that matters and ground speed is what it is at the moment of take-off or landing.

+1 for mentioning why both are important

It should be noted that groundspeed is also important during takeoff... if you're rejecting the takeoff.

The Wikipedia article on indicated airspeed has a good description. An airspeed indicator is actually more of a "dynamic-pressure" meter, with the dynamic pressure converted to airspeed.
Dynamic pressure is $q=\frac{1}{2}\rho V^2$ where $\rho$ is density and $V$ is airspeed.
The Wikipedia article on the lift coefficient explains that lift is proportional to dynamic pressure, the area of the wings, and the lift coefficient, which in simplified terms can be considered a function of the angle of attack.
$L=\frac{1}{2}\rho V^2 S C_L(\alpha) = qS C_L(\alpha) $
The takeoff speed is the speed at which you will have enough lift to get the airplane off the ground at the angle of attack that the airplane will have post-rotation. So, for a given aircraft at a given weight, wing area, post-rotation angle-of-attack, and lift curve, you will be able to take off at a particular dynamic pressure.
In fact, all the aerodynamic forces on the aircraft are proportional to the dynamic pressure. So that's why stall speed, never-exceed-speed (above which the aerodynamic forces could start damaging the aircraft structure), etc. are all given in indicated airspeed - because it's a proxy for dynamic pressure.
True airspeed is the speed of the aircraft relative to the air mass it's flying through and can be calculated from indicated airspeed by correcting for density and temperature. Your ground speed is then the true airspeed added to the wind speed.

The IAS includes factors such as Wind Component (Tail, Head or Cross), Pressure and Temperature. All these have an influence on your takeoff. The takeoff Speed Vr is calculated as Indicated Airspeed. Imagine you have a Headwind Component of +50. You Groundspeed would be way lower than your Airspeed. What counts is the amount of air that flows over the wing in order to takeoff, not the speed relative to the ground.

It is important to note that along with speeds such as v_rotate, predicated on IAS, there are critical speeds on takeoff that are essentially, solely or predominately functions of ground speed. Refusal speed is one. Maximum brake energy speed is another.
V1 is a speed for which ground speed is a critical component, since it is a function of runway remaining and whether it'd be possible to stop, or to be able to continue the takeoff with a lost engine.
The reason we don't use ground speed in determining when we've passed them has to do with what is available to the pilot in the cockpit to look at and safely make decisions with during the takeoff.

before we have to remove this answer for unfriendliness, could you consider rephrasing?

Updated to make more friendly.


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What does an XXXX ident mean?
A couple of guys who I met online yesterday claim to have been in the military. One of them was tracking flights earlier and saw a plane with a callsign of XXXX. He said that this was very bad and is seen only rarely, specifically during war. Is he right, or is it April Fools? What does 4X mean?

I think he's just messing with you. The "ident" you're referring to, is merely a field built into the transponder that allows the operator to enter their registration. My guess is either this was done wrong in the aircraft or the receiving equipment mangled it. Just to note this isn't something normally done by the pilots, either - it's pre configured as part of the installation

Do you mean "XXXX" literally or as a placeholder for something?

"The problem with the internet is that it is hard to tell the truth from the lies." -Abraham Lincoln

This is listed literally as its callsign and the people I spoke to approached it as a literal callsign, not a placeholder.

It means the pilot is hanging out for a very average Queensland mid-strength beer?

Either the person you are talking to is misleading you, or the software they are using to track aircraft is inserting "XXXX" as a placeholder because it does not know the true callsign.
ICAO Annex 10 Volume 2 Chapter 5 discusses the standards for aviation call signs:

5.2.1.7.2 Radiotelephony call signs for aircraft
5.2.1.7.2.1.1 Full call signs
An aircraft radiotelephony call sign shall be one of the following types:

Type a) — the characters corresponding to the registration marking of the aircraft; or
Type b) — the telephony designator of the aircraft operating agency, followed by the last four characters of the registration marking of the aircraft;
Type c) — the telephony designator of the aircraft operating agency, followed by the flight identification.

It is theoretically possible that "XXXX" could be the registration marking on a specific aircraft, but if you look at a list of registration prefixes you will see that "XX" is not a valid prefix.
Military callsigns will similarly be either a portion of the registration or inventory number of the aircraft itself (such as Navy 12058), or a "mission" callsign consisting of a pronounceable word and a number (such as DOOM41).
An aircraft's callsign can be transmitted via ADS-B, but in a combat scenario a military aircraft would not be transmitting at all.


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I have a PPL in Australia and own a plane. I am wondering if I am legally allowed to hire my plane out to other pilots and make money?
I have found multiple answers that state I can lease to a school and things like that but I need to know if I can hire my plane out privately to other pilots (I.e mates) And actually make a profit from this. I won’t be flying it to make profit just through the hire costs. Note: I am in Australia and it’s an experimental (vans rv6)
Thanks!

I assume as you're in Australia you're interested in casa regs not faa regs (I've retagged as appropriate)

Ahh legend thank you. What are the rules where you’re located?

You can start off by consulting this page.

In our area, the FAA rules allow you to rent or lease your own plane to other people or organizations. But, the plane would have to have standard category certification. So, an experimental like the Vans RV6 would not work. Also, you can not mix or share the flight time as a private pilot. That would put you in a gray area of flying for compensation. The problem would be with insurance. Will your policy allow it? They may require you to be in the aircraft as PIC at all times, or for you to do checkout flights with each client. Which would put you back in the gray area.

You could start your own non-equity flying club. Or, you could make the rental a commercial enterprise. Either way, I would not let anyone fly your plane while the plane is in your name as owner. Put the aircraft into a corporate entity name for liability purposes. Also, hire a CFI to perform checkout flights. I personally know of at least two people who have done this. One of which is a non-pilot who bought the aircraft for their aspiring pilot son. Now, they have grown to be a multi-plane flight school and rental company. Some of them leased from other pilots.


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If the profile of a wing pulls a plane up, why can planes fly inverted?
I'm simplifying here, but every introduction to flying shows us that the profile of a wing leads to lower pressure on the upper side of the wing, hence the wing and the plane attached to it will be pulled up.
All right.
How does that explain a plane flying inverted? If the explanation was right, the plane would pull itself towards earth.

obligatory XKCD: http://xkcd.com/803/

Normally, an airfoil is optimized for best lift/drag (L/D) efficiency for a certain flight profile (usually a compromise). Since most of the time for most aircraft inverted flight is not an issue, you get an airfoil that is optimized for upright flight, and this is best achieved with asymmetric geometries.
However, depending on the angle of attack any airfoil can (and will) generate "negative" lift, only much less efficiently so, than for the optimized regime,  resulting in increased drag.
The desired angle of attack for conventional aerodynamically controlled aircraft is maintained by the elevator. For symmetric airfoils commonly used for aerobatic planes, the performance for upright and inverted flight is quite similar. For 99% of all other airfoils inverted flight will work up to a certain point, depending on the available power, CG, the maximum lift and rudder forces availabe before stall. As a result, for some aircraft, a stable inverted flight cannot be maintained, while for others it could be (but with varying penalty to performance, stall speed etc). The aerodynamical possiblity of inverted flight is of course limited by structural and other considerations.

There is no such thing as 'negative lift'.  The wing produces a force (lift) equal the acceleration of a mass of air away from the flight path times the mass of that air.
To fly in level flight this mass x acceleration vector is equal and opposed to the acceleration of gravity.
It matters not if the shiney side of the airplane is facing the sky or the ground.

@JimInTexas thus the quotation marks.

@JimInTexas Of course there is such a thing as negative lift. Force is a vector quantity, having both a direction and a magnitude. For the direction to be meaningful, it must be defined in relation to some frame of reference. Defining it relative to the airfoil is generally most useful for aerodynamics. Generally, this frame of reference will be defined such that 'the shiny side' is considered positive. Thus, at AoA such that lift is produced in the other direction (regardless of the orientation of the foil with respect to the ground,) the lift vector will indeed be negative.

@reirab perhaps I should work on this answer to remove some of the fuzziness - or feel free to edit.

@yankeekilo The answer seems fine to me. I was just addressing Jim's comment.

@reirab appreciated :D

This relation between a wing's curvature and a pressure difference on both sides is often part of the 'equal transit time' explanation; air on the curved side has to traverse a longer distance in the same amount of time, therefore goes faster, which leads to a lower pressure. This explanation is very common and completely wrong.
In normal flight, pitching the nose up causes the aircraft to climb because the wings meet the air at a steeper angle; the lift increases. It makes sense that rotating the wings in the opposite direction decreases lift. In fact, point the nose down far enough and the wings will produce no lift at all. Beyond that, the generated lift becomes negative and the wings will start to pull the aircraft down.
During our hypothetical manoeuvre, our attitude has varied by about 10°. That's not exactly flying upside down yet, the curved side of the wings were on top the entire time. Whether or not the lift was pointing up as well, depended on the angle at which the wings meet the air, the angle of attack.
The same is true for inverted flight. If we find ourselves at an attitude where the wings are pulling us down, we raise the nose. At first, the downward lift will disappear and at higher angles of attack, start pointing up and grow larger. At sufficient airspeeds and angles of attack, we have enough lift to maintain altitude upside down.
So why do wings need to be curved at all? They don't. Flat wings also provide lift at non-zero angles of attack and are perfectly usable, but not very efficient. Properly shaped airfoils create more lift and less drag. To find out why, consult a more accurate explanation of how planes really fly.

See my follow up: http://aviation.stackexchange.com/questions/1157/why-is-the-wrong-explanation-of-air-travels-a-longer-distance-and-creates-a-lif

I know this answer is over a year old, but I must commend Marcks for coming up with (or finding) an answer more 'true' yet understandable.

There's even a nice GIF demonstrating that the "equal time of flight" is simply false: https://upload.wikimedia.org/wikipedia/commons/9/99/Karman_trefftz.gif

FYI. The T-38 wing is symmetrical. i.e. there is no "extra distance" for air flow over the top of the wing. However,  when in level flight the aircraft is actually about 2-3 degrees nose up.

@romkyns This video is a better demonstration, since it shows an actual physical set up. The dots in that GIF could have been programmed to move in any way at all. (OK, they do seem to be an accurate representation but animated dots follow the will of their animator.)

Short answer is that explanation is wrong. How planes actually generate lift is far more complicated.

I'd say it is simpler.  Lift is created by making air go down.

@2NinerRomeo assuming that's true (which it isn't) the question of how planes make air go down is also complicated.

Maybe you like the panel method, circulation theory, or the Prandtl lifting line theory.  Maybe you’d like to quibble about the reference frame for defining “down” or what counts as a “push” or a “pull”  maybe you’ve implemented a Navier-Stokes solution for finite wings. At the end of the day, if you’ve made lift, you’ve altered the momentum of the air that you’ve moved through.   I suggest instead of saying “Bernoulli is wrong” or anyone else for that matter, acknowledge the merits of their argument while offering your refinements.  People will find it informative and your rep will improve.

To make my point clear, the concept of lift can be expressed simply.  When it comes to derivation of a quantitative model with usable fidelity, I would agree that greater complexity is involved.

Bernoulli's Principle (airfoil shape) is only one of the lifting forces.
Equally important is deflection (Newton's law), and on propellor aircraft, accelerated airflow.

Please consider expanding your answer. At its current state it is correct, but too general to be useful if the reader is unfamiliar with the topic.

Newton's law of lift is plain wrong. It starts to become correct at hypersonic speed, but at the low speeds Newton had in mind he was just guessing what happens, and guessed wrong. Maybe you mean Newton's first law of motion? Then it would be more illuminating to talk of an impulse transfer between aircraft and air.

'Newtonian' lift is the upward reaction of the wing to its downward deflection of the air-stream.  The most efficient way to deflect the airstream is a gradual acceleration, accomplished by a concave lower surface.  The upper surface shape must prevent premature 'separation' (chaotic vacuum eddies) of the upper airflow.  A symmetric wing can still deflect the air-stream, depending on its angle-of-attack; it has the same lift and drag whether right-side-up or inverted, which is not as efficient as a right-side-up normal wing, but better than an inverted normal wing.


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How to land a sports plane with tailwind?
Let's say we have a Cessna 150 or some other lightweight two seater and no chance to land with head wind for whatever reason.
We're trying to land with a constant tailwind of 7 knots.
I would try to land as close to stall speed as possible to compensate the tailwind. So much for the theory. In reality, the wind is not constant. If I'm close to stall, dying wind will give me trouble. What's a general good approach for such situations? What configuration would you choose?
If the runway is very long, one can just go faster. But often, runways are rather short.

Land normally.  Check your POH (Pilot Operating Handbook) first to ensure you have enough runway including the extra needed for a tailwind.  The only thing to watch out for is that winds tend to moderate as you get closer to the ground.  In a headwind landing, the relative wind will decrease, In a tailwind landing the relative wind will increase, so there will be an increased tendency to float way down the runway.  Be on speed for a short field landing technique.

If the absolute velocity of the tailwind were to decrease as you neared the ground, you should use less runway than if it stayed steady.  Your airspeed will remain the same, but your ground speed will decrease as the tailwind decreases.

oh no! Not really. Inertia will still have you moving forward and your IAS will (momentarily) increase. It will take a few seconds for the airplane to reduce back to it's original IAS

You should never try to land "as close to stall speed as possible".
Manufacturers have a recommended approach and landing speed for a reason.  It is a compromise between a safe margin over stall speed, aircraft controllability, and landing distance.  You should use their experience with the airplane by following their recommendations.  Sometimes they have adjustments because of the wind, sometimes they don't because they don't feel that they are necessary.
Follow the recommended procedures and the POH/AFM will tell you the performance that you can expect. Do anything else and you are flying in an uncharted area (literally) and can find yourself in trouble.
Also, make sure that you check to see if there is a limitation for a maximum tailwind component for the specific airplane.  If you exceed this, you can run into controlability issues or exceed the maximum speed that the tire is rated for.
In short, just fly by the book and be aware that you will use more runway so be sure to check the operating handbook to stay safe.

By "as close to stall speed as possible" I of course meant the recommended speeds.

Well, the recommended landing speed is usually 30% above the stall speed, so those are very different speeds.  :-)

@Lnafziger: That's definitely the case for all jets and any other airliners, but I've seen instruction videos for small planes saying stall warning should go off during flare and while propeller aircraft decelerate faster, loosing 30% of speed from threshold to touch down sounds to me as too much, especially since it's in ground effect.

@JanHudec I still stand by my answer: use what is in the POH/AFM for the airplane, whatever that value may be. :)

@Lnafziger: Definitely.

One thing that is an eye opener to people in regard to tailwind landings is when I ask them about wind gradients at low altitudes:
Wind is actually (supposed to be) measured about 10 meters above the runway. Because of surface friction that wind speed is going to decrease dramatically as you approach the runway surface. If that wind is a tailwind, as you approach the runway and flare your tailwind decreases and your indicated airspeed does what? increases, that's right.
So not only your ground speed is higher, but you just got a speed bump during your flare leading to a longer float.

The major problem with landing light aircraft, especially tail draggers with no steerable nose wheel,and tailwind component,is the lack of control when roll-out speed drops to that component or below.
In fact,below it,control actions reverse! This is often more important than the higher touch-down speed, due to  uncontrollable lateral departure from the runway,but at a relatively low ground speed.

Land normally per the POH is the correct answer per accepted answer.  Just remember that your ground speed will be faster and roll out will be longer. You'll pass the turnoff you usually make with a headwind.

It's not a huge problem if the wind is not too strong and there is plenty of runway.  Ignore perceptions of groundspeed and land normally according to airspeed.  I've conducted some experiments that actually tend to result in smoother landings with a tailwind component than with a headwind component; the wind gradient (which tends to increase or maintain the airspeed as you descend with a tailwind component) may be a significant factor in this.  With
a tailwheel aircraft, there is a risk of a groundloop as you slow down when landing with a tailwind.  Don't do full-stop landings in a tailwheel aircraft with a tailwind if you can avoid it; a slight tailwind can often be tolerated for touch-and-goes.  But a 7 mph tailwind should not be a problem for a Cessna 150 or similar tricycle-gear airplane if the runway is long enough and you use appropriate techniques.
Comments in other answers about the wind gradient tending to increase the float distance when landing downwind are definitely on target.  Keeping the approach speed fairly close to the stall airspeed (e.g. 1.3 * Vso) will shorten your float and rollout distance.  But definitely carry a bit of extra airspeed for safety if the wind is gusty rather than steady.
It's also worth noting that the wind gradient will decrease your climb rate on a go-around from a downwind landing, so the climb angle may initially be very poor.

Tailwind Landings are performed like any other landings.  Bear in mind your groundspeeds will be higher than normal and you will have to anticipate higher rates of descent on final to maintain glidepath as well as a longer rollout once on the ground.
Performance wise, you will need to consult the airplane flight manual for the aircraft for short or confined field landing procedures as well as calculating landing distances.  Do NOT attempt to land at or very close to the stall speed of the aircraft; follow the manufacturer recommended approach speeds Vref for your airplane and fly this plus a gust factor if needed on final.  If an approach speed for short or confined fields is not listed for your light airplane, never fly final slower than 1.3*Vso + gust factor.  You will need a small kinetic energy reserve in the roundout to arrest the rate of descent and place the airplane in the correct attitude for touchdown.  If you are at or very close to Vso on final, you will not be able to arrest your descent without exceeding the critical angle of attack, resulting in a hard landing or potentially a crash.
Tailwinds do have the unpleasant side effect of greatly increasing the approach and landing roll; typically they tend to increase this by 10% for every 2 knots or so of tailwind as compared to landing in still air.  Doubly unfortunate is that runways where there is no alternative but to make a tailwind landing tend to be one way in fields, often very short in length, with points of no return on approach.  If these performance considerations are pushing up against the performance capability limits of the airplane and/or pilot, it would be wise to thoroughly evaluate this as part of your preflight risk management and select another day with more favorable winds to make the trip on.


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Are customs stops required for private flights within the Schengen Area?
I would like to make a VFR flight from Switzerland to Germany and Germany to France and then France to Switzerland.
For the first step: Switzerland to Germany I know that I have to fill a custom form AND a flight plan while taking off and landing on an airport with custom services. The same for France to Germany.
HOWEVER from Germany to France is this rule applicable (note that the plane is registered in Switzerland)? I cannot find an official website?

The European Union has also something called EEA - European Economic Area. Within the EEA it is not required to fill out anything except a flight plan between Germany and France.
Switzerland, as stated, is not part of the European Economic Area and therefor customs are required.
Just in addition, Schengen is for passport free travel and not for taxes.

Schengen may be passport-free but you still need to be able to prove your country of residence, a passport or a "National Identity Card" are valid forms of residency, so you do need to take some documents with you.

so custom is required between France and Germany if the plane if registered in Switzerland?, apologies but the answer is not clear to me

It’s not about where the plane is registered, it’s about from where you come. No customs within the EU.

@branchwarren you'd pass customs when bringing the plane into the EU from Switzerland, not when subsequently flying it between EU nations. It gets more complicated in this specific case as Switzerland is not part of the EU but is part of the Schengen common customs region...


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Do Jeppesen SIDs have top altitude?
FAA SID charts show the top altitude, the maximum altitude you can climb to when cleared for the SID. Do Jeppesen SID charts also show the top altitude? I checked some of them but couldn't find it. If Jeppesen charts do not show it, how do you know the maximum altitude for SIDs?


text:
Is a magnetic assisted takeoff feasible?
I have seen that there are many companies working toward hybrid electric aircraft. It is very exciting some of the ideas.
The primary reason seems to be for limiting CO2 emissions acceleration, especially during take off. In theme parks acceleration is often performed by powerful magnetic forces.
I was wondering if in the long run a powerful electro-magnetic system could pull planes, fitted into a track on runways for take off?

The takeoff only accounts for a fraction of the fuel usage of an average flight. I doubt limiting CO2 emissions specifically during takeoff is the primary reason for developing hybrid planes.

See also https://aviation.stackexchange.com/questions/31048/ and https://aviation.stackexchange.com/questions/77749/

@expeditedescent the thing to keep in mind is that when a system is extremely optimized for efficiency, it can reach the point where a non-trivial part of the overall consumption/emissions come from one brief mode where it has to operate far less efficiently.  So you see attention to even things like taxing around, and hotel loads while waiting for a slot.  Also ground and near-ground operations create a localized concentration of emissions.

Catapults are used to launch airplanes on aircraft carriers, most are currently steam powered but the US Navy are developing an electronic catapult system called EMALS to replace steam ones in the future. Other countries are developing the same technology. The US Navy system has been shipboard tested, apparently there are still some problems but they will likely get worked out, so the technology is viable - it is possible.
Shipboard catapults are used to accelerate airplanes quickly in the very short distance you have on an aircraft carrier deck, not to save energy or fuel. It doesn't make practical or economic sense to use the technology to accelerate airplanes in a normal airfield for the following reasons:

It's very expensive technology to buy and maintain. It would cost enormous amounts of energy to deploy this technology
It will limit airplane operations to those airfields which have the technology. I can fly a Cessna 172 into and out of remote strips, but if I require a catapult of some kind my options become very limited
It doesn't actually help much. It's not the take-off roll which is energy intensive, it's the climb to altitude, and a catapult wouldn't help with that. When you think about it the take-off roll is a minute, climbing to altitude is 20 minutes in a commercial jet, you'd be reducing the energy needed by at most 5%, which isn't worth the investment

The engines would still be running, and probably at climb power, during the "cat shot," so you're only saving fuel by reducing the time spent getting from 0 to flying speed - some of the 'on the runway' fuel burn still happens.

That's got me wondering about using TGV locos for a 200 knot 10000 feet version of a glider tow!

I'm sure passengers would love that experience @BrianDrummond

@Brian Drummond: Why think small?  Use a rail gun: https://en.wikipedia.org/wiki/Railgun

I don't think we want to turn the passengers to sludge @jamesqf

An important consideration with catapult launches is that they're used to reduce required runway length.  To use a catapult, one would either have to have enough runway to allow a plane to safely stop if after being catapulted it would be unable to develop enough power to get and remain airborne, or else accept the fact that the plane will go off the end of the runway in such cases.  If a carrier-launched jet is unable to climb after catapulting, the pilot can eject and let the plane fall into the ocean, but such a contingency plan would be unacceptable in civil aviation contexts.


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Piper Cherokee - Flying with inoperative equipment
I've looked everywhere and I'm not able to find the relevant information regarding the following.
What equipment can be inoperative and still allow me to fly a pa-28-181? I know the rules in the 91.213 and to placard the inoperative equipment, etc.
But my question is, which specific equipment is required for flying day/night VFR (PPL)? There is no MEL for most GA aircrafts, such as the pa-28-181s.
For example, if the landing light isn't working, I can probably still fly day VFR but I can't fly if the altimeter isn't working.
I was told that there is a flow checklist that helps answer whether a specific inoperative equipment is required or not for the cherokees but I can't find it. Any guidance would be helpful.
P.S.: I'm preparing for my checkride and am trying to checkoff the PA.I.B.K3a item on the ACS.

Depending on the type of airspace you’d be flying in, I don’t see why you’d need an altimeter.

@757toga -  Ok.  Required by regulation.  It’s been too long I guess…

Ahh yes!! That's exactly what I was looking for FAA AC 91-67! @757toga . If you post that as an answer, I'd be happy to accept it.

Since you mentioned 91.213, I'm going to assume you're talking about the US, since you didn't specify the jurisdiction.
The required equipment for VFR is outlined in 14 CFR § 91.205 The exact answer depends on the type of flight.
For VFR day flight, you will need:

Airspeed indicator.
Altimeter.
Compass.
Tachometer for each engine.
Oil pressure gauge for each engine using oil.
Temperature gauge for each liquid-cooled engine.
Oil temperature gauge for each air-cooled engine.
Manifold pressure gauge for each altitude (turbocharged) engine.
Fuel gauge for each tank.
Landing gear position indicator, if the aircraft has a retractable landing gear.
An anticollision light system (if the plane was certificated after March 11, 1996).
If operated for hire over water and beyond power-off gliding distance from shore, approved flotation gear.
Seat belts
An emergency locator transmitter.

For night VFR flight, you need all of the above, plus:

Approved position lights.
An anticollision light system (if certified after August 11, 1971).
Landing light.
An adequate source of electrical energy.
One spare set of fuses, or three spare fuses of each kind required.

In determining which equipment can be inoperative in flight the following information should be looked at:

91.213 required equipment for day, night and IFR flight
Minimum equipment list - Items that can be inoperative and still be airworthy for dispatch)
Equipment list - Items installed at the time of certification.  Will list items that are required for dispatch and those items that are in addition to the requirements for dispatch
Kinds of operation list - Equipment required for a specific operation.

The PA-28 airplane most likely doesn't have a MEL.  It does have an equipment list as located in Section 6 of the POH.


text:
A429 label 044, DME Identity Presence - Definition
Is there a bit by bit definition for the A429 label 044, DME Identity Presence?
I have this label 044 coming out of a Collins DME-4000, but it is not defined in its documentation I have at hand (installation manual). Only distance, IDENT, tune echo, etc. are defined.
Now, since this label is there, I'm interested what its contents are, this is not a standard label defined in the A429 specification. Hence my question: Is there a bit by bit definition for the A429 label 044, DME Identity Presence?
I know from a different installation manual at least that the label is used for "DME Identity Presence". I was just hoping the keywords "label 044" and "DME Identity Presence" rings a bell for someone who then would kindly provide a bit by bit definition from a source that I just don't have (or at least haven't found, yet).

That particular label description doesn't show up in my copy of ARINC 429. It may be in a newer version or in the installation or equipment manuals for the DME-4000 if it is a custom designed label. It should at least be a BCD label, so I would probably start there.

Thanks @selectstriker2! I have hands on a CMM of the DME, but it isn't mentioned even there. I feel lucky that at least in some documentation I found the definition "DME Identity Presence" so that at least I have a hint for the direction to look for. So far, without success.

I can't answer the specific question, but can provide some insight. The Proline 21 radios were designed to handle a wide variation of configurations. To 'simplify' installations, there was an option to connect the radios to an RIU-4x00 (radio interface unit), which then connected to controls, displays, and other systems. To make it all work, there were a number of ARINC 429 labels that were added and some remapped so they could be combined on a single bus. The RIU handled most of it internally. I expect the label you're seeing provides configuration information to the RIU.

Thanks for that insight! Yes, I can confirm there are a lot more labels on the bus which are not documented. Since I only found at least a description for label 044 (DME Intentity Presence) I thought I give it a try and ask here if somenbody knows something about it. In the end, I would like to display something in the IDENT Area of the Proline 21 PFD. But I figured, sending the documented label 300 is not sufficient. So I thought label 044 will do the trick. Which it didn't...


text:
Will a cell phone violation interfere with getting my pilots license?
Today I received a traffic ticket for using my cell phone while driving. This is the only ticket I have. Will this interfere with getting a pilot license?

This is in California. I got a using a cell phone while driving. First offence.

No. You don't even need to report it unless they took action against your license or required you to take a class. From the MedXPress guide:

Individual traffic arrests and/or convictions are not required to be
reported if they did not involve: alcohol or a drug; suspension, revocation, cancellation, or denial of driving privileges; or attendance at an educational or rehabilitation program.

No, a single ticket like that will be entirely inconsequential.
The FAA cares (a lot) about DUI tickets, and perhaps years of scofflaw behavior with repeated violations and a blatant pattern of incorrigible behavior might get their attention, but one traffic ticket? No issue whatsoever.

Just an FYI: "scofflaw" is not a term that's really known/used outside of NA.

@Jamiec Interesting, thanks.  Not a term that I use often enough to have learned that previously.  For other readers outside North America, dictionaries define it as "a contemptuous law violator" and "a person who flouts rules, conventions, or accepted practices."


text:
Does the 300 hp IO550 conversion require an auxiliary tank on the Cessna 182?
Does the 300 hp conversion with a continental IO 550 always require an auxiliary tank when used on a Cessna 182?  I see some of these conversions indicate an auxiliary tank is present under pilot seat but I would like to try to avoid this.

This article gives a slightly dated (2002) overview of the engine upgrade options for a 182. There's no mention of auxiliary tanks being required, but it does note that for at least one option they're typically a good idea:

The IO-550 engine is a guzzler and if you don't have long-range tanks,
  you'll need them. Indeed, you'll probably want to consider Flint tip
  tanks for your Skylane.

It's possible that you've seen conversions where, for whatever reason, a cabin tank was added instead of - or even in addition to - tip tanks.
If you're looking into an upgrade then if you aren't already a member you should consider joining the Cessna Pilots Association and search through their forums (members only) for whatever you can find. I found one thread on upgrading the C182 to an IO-550 but it didn't mention the fuel tanks at all, although I didn't search thoroughly.

I don't think so. The modification is done in accordance with AIR PLAINS STC SA00152WI, which has no mention of any auxiliary fuel tank in the 'parts installed' section.
Also, the document says,

Fuel flows by gravity from the wing tanks to a four position selector valve..

There is no mention of auxiliary fuel tank anywhere.